Study Questions:

What are the temporal trends in the use and costs of cardiac imaging for the examination of patients with heart failure (HF) in Canada?

Methods:

The study authors conducted a repeated cross-sectional study, using population-based administrative databases in Canada, of individuals with HF identified using a validated algorithm based on hospital admissions and ambulatory physician claims between April 1, 2002, and March 31, 2017. The study authors examined the use of resting and stress echocardiography, myocardial perfusion scintigraphy (MPS), and invasive coronary angiography (ICA) (all of which were referred to as traditional modalities). They also examined the use of coronary computed tomography angiography, cardiac magnetic resonance imaging (MRI), and cardiac positron emission tomography (PET) (all of which were referred to as advanced modalities).

Results:

The final study cohort was comprised of 882,355 adults (50.1% women; median age, 76 years [interquartile range, 66-83 years]) with prevalent HF. The age- and gender-standardized prevalence of HF remained stable during the study (2.4% [95% CI, 2.4%-2.4%] in 2002 and 2.0% [95% CI, 2.0%-2.0%] in 2016). There was an increase in the rate of use of resting echocardiography, from 386 tests (95% CI, 373-398) per 1,000 patients with HF in 2002, to 533 (95% CI, 519-547) per 1,000 patients in 2011. Coinciding with the initiation of an accreditation program for echocardiography in 2012, there was an immediate reduction in the rate of use (−59.5 tests per 1,000 patients with HF; p < 0.001), which was followed by a plateau in subsequent years. At the same time, there was a 10.8% relative reduction in the use of MPS (95% CI, 66-73) per 1,000 patients with HF and remaining stable thereafter (p = 0 .008), and an 11.2% relative reduction in the use of ICA from 2011 to 2016 (95% CI, 61-68) per 1,000 individuals with HF (p = 0.75), and the incorporation of newer modalities after they became publicly insured health services.

Conclusions:

These findings suggest that resting echocardiography remains the most used imaging technique for patients with HF, exceeding the use of and the cost spent on other modalities. Stabilization in the use of traditional imaging modalities coincided temporally with the emergence of advanced techniques and provincewide quality improvement policy initiatives.

Perspective:

This study suggests that traditional modalities will continue to be the bedrock, given that interpretation of these studies is a part of the core training of cardiologists and due to the ease of use. The utilization of imaging resources, however, will continue to evolve as the population ages, with recognition of newer etiologies of HF such as chemotherapy-induced myocarditis, as natural history of HF continues to improve (for example, better survival of human immunodeficiency virus cardiomyopathy or HF due to adult congenital heart disease or HF due to any cause), as hybrid scanners are increasingly available (for example, PET and MRI in one scanner may be a better option for sarcoid or to determine viability), as newer quality measures and appropriateness criteria emerge, and as costs of ‘advanced’ modalities continue to fall.